From fb94d2da92ff9b87881a547a1c72841ad841b8c8 Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Thu, 24 Mar 2022 19:50:54 +0800
Subject: [PATCH] [td-14266] fix bug.

---
 source/common/src/ttime.c                   | 24 +++++++++++++++++----
 source/libs/executor/src/executorimpl.c     |  2 +-
 tests/script/tsim/query/interval-offset.sim |  1 +
 3 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/source/common/src/ttime.c b/source/common/src/ttime.c
index 22c10f62b4..da1adf0c59 100644
--- a/source/common/src/ttime.c
+++ b/source/common/src/ttime.c
@@ -458,16 +458,21 @@ int64_t taosTimeAdd(int64_t t, int64_t duration, char unit, int32_t precision) {
   if (duration == 0) {
     return t;
   }
-  if (unit == 'y') {
-    duration *= 12;
-  } else if (unit != 'n') {
+
+  if (unit != 'n' && unit != 'y') {
     return t + duration;
   }
 
+  // The following code handles the y/n time duration
+  int64_t numOfMonth = duration;
+  if (unit == 'y') {
+    numOfMonth *= 12;
+  }
+
   struct tm tm;
   time_t    tt = (time_t)(t / TSDB_TICK_PER_SECOND(precision));
   taosLocalTime(&tt, &tm);
-  int32_t mon = tm.tm_year * 12 + tm.tm_mon + (int32_t)duration;
+  int32_t mon = tm.tm_year * 12 + tm.tm_mon + (int32_t)numOfMonth;
   tm.tm_year = mon / 12;
   tm.tm_mon = mon % 12;
 
@@ -574,12 +579,23 @@ int64_t taosTimeTruncate(int64_t t, const SInterval* pInterval, int32_t precisio
     }
   }
 
+  ASSERT(pInterval->offset >= 0);
+
   if (pInterval->offset > 0) {
     start = taosTimeAdd(start, pInterval->offset, pInterval->offsetUnit, precision);
     if (start > t) {
       start = taosTimeAdd(start, -pInterval->interval, pInterval->intervalUnit, precision);
+    } else {
+      // try to move current window to the left-hande-side, due to the offset effect.
+      int64_t end = start + pInterval->interval - 1;
+      ASSERT(end >= t);
+      end = taosTimeAdd(end, -pInterval->sliding, pInterval->slidingUnit, precision);
+      if (end >= t) {
+        start = taosTimeAdd(start, -pInterval->sliding, pInterval->slidingUnit, precision);
+      }
     }
   }
+
   return start;
 }
 
diff --git a/source/libs/executor/src/executorimpl.c b/source/libs/executor/src/executorimpl.c
index cc0683f344..09ffce2837 100644
--- a/source/libs/executor/src/executorimpl.c
+++ b/source/libs/executor/src/executorimpl.c
@@ -7576,7 +7576,7 @@ SOperatorInfo* createIntervalOperatorInfo(SOperatorInfo* downstream, SExprInfo*
   }
 
   pInfo->order     = TSDB_ORDER_ASC;
-  pInfo->precision = TSDB_TIME_PRECISION_MICRO;
+  pInfo->precision = TSDB_TIME_PRECISION_MILLI;
   pInfo->win       = pTaskInfo->window;
   pInfo->interval  = *pInterval;
 
diff --git a/tests/script/tsim/query/interval-offset.sim b/tests/script/tsim/query/interval-offset.sim
index 9d5466ecbf..b6bdcca68f 100644
--- a/tests/script/tsim/query/interval-offset.sim
+++ b/tests/script/tsim/query/interval-offset.sim
@@ -88,6 +88,7 @@ print ===> rows5: $data50 $data51 $data52 $data53 $data54
 print ===> rows6: $data60 $data61 $data62 $data63 $data64
 print ===> rows7: $data70 $data71 $data72 $data73 $data74
 if $rows != 8 then
+  print expect 8, actual $rows
   return -1
 endi 
 if $data00 != 2 then